The present disclosure relates generally to turbocharger systems for internal combustion engines. The disclosure relates more particularly to methods for assembling together components of a turbocharger system, and to various subassemblies of a turbocharger system.
Exhaust gas-driven turbochargers are commonly employed for boosting the performance of internal combustion engines. A typical turbocharger includes a compressor having a compressor housing containing a compressor wheel, a turbine having a turbine housing containing a turbine wheel, and a shaft connecting the turbine wheel to the compressor wheel. The shaft is supported in bearings housed in a center housing that is bolted to both the compressor housing and the turbine housing.
Typically, the exhaust gases discharged from the cylinders of the engine are collected in an exhaust manifold that leads to an exhaust pipe, and the exhaust pipe is coupled with one or more turbochargers for delivering exhaust gases to the turbine(s) of the turbocharger(s). When there are multiple turbochargers, various arrangements including serial, parallel, serial-sequential, etc., have been proposed. In some cases, a valve is arranged between the exhaust manifold and one of the turbochargers for selectively allowing or preventing flow of exhaust gases. The valve typically has a housing bolted to the exhaust manifold and to the turbine housing of a turbocharger.
In these types of turbocharger/engine systems, there are various subassemblies of components that typically are preassembled. For example, in the case of the valve described above, the valve can be preassembled with the exhaust manifold to form a subassembly, and subsequently a turbine housing of a turbocharger can be bolted to the exhaust manifold using bolts that pass through holes in a housing of the valve and into holes in the manifold. Alternatively, the valve can be preassembled with the turbine housing, and that subassembly then can be assembled with the manifold and other components of the system. As another example, during assembly of a turbocharger, the center housing can be preassembled with the compressor housing or with the turbine housing, and/or a variable-nozzle mechanism can be preassembled with the center housing. In such preassembly operations, the components of the subassemblies are placed in predetermined positions with respect to each other and are secured in such positions with suitable fasteners such as metal screws, metal pins, metal clips, or the like.